Rose of Sharon, Shrub Althea 'White Angel'

Let's straighten things out on this plant. It is not H. syriacus, but a cross between a plant of Hibiscus rosa-sinensis pollinated by H. ...Read Moresyriacus 'Diana', an introduction from the National Arboretum. It was created by Dr. Sam McFadden around 2004. Its cultivar name is 'Grewa', and White Angel is the trademark name, owned by Greenleaf Nursery. You cannot put a trademark name in single quotes as if it was a cultivar name. Although supposedly hardy in zone 5, that seems unlikely given the parentage. Maybe someone who has grown it in zone 5 can comment on that! It should be listed as Hibiscus hybrid, or as Hibiscus rosa-sinensis x syriacus 'Grewa'.